Decoration lamp



FIG. 1 is the front perspective view of a decoration lamp showing my new design (please be informed that the rear perspective view is the same as the front perspective view of the new design);

FIG. 2 is the left perspective view thereof (please be informed that the right perspective is the same as the left perspective);

FIG. 3 is the top elevational view thereof;

FIG. 4 is the bottom elevational view thereof; and,

FIG. 5 is the three-dimensional view thereof. 

The ornamental design for a decoration lamp, as shown and described. 